Closed magnetic core blowout with series coils



April 22, 1958 J. D. WOOD ,8

CLOSED MAGNETIC CORE BLOWOUT WITH ssams cons Filed Nov. 9, 1955 3 Sheets-Sheet l I c;- E

IENTOR. JOSEPH 0. W000 A ril 22, 1958 v J. D. W000 3 CLOSED MAGNETIC CORE BLOWOUT WITH SERIES COILS Filed Nov. 9,1955 3 Sheets-Sheet 2 11m a'apov/ Alas/via X/I/YJ IN V EN TOR.

J 035 Ph' 0. W000 April 22, 1958 J. D. WOOD 2,

CLOSED MAGNETIC CORE BLOWOUT WITH SERIES COILS Filed Nov. 9, 1955 3 Sheets-Sheet 3 IN VEN TOR. JOSEPH .0. W000 CLOSED MAGNETIC CORE BLOWOU I SERIES COILS Joseph D. Wood, Wayne, Pa., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania WITH Application November 9, 1955, Serial No. 545,956 g 17 Claims. (Cl. 200-147) My invention relates to a magnetic structure for circuit breaker arc chutes and more particularly to a closed magnetic core structure having energizing coils to create fluxes in bucking relationship within the closed core to thereby create a flux in the arc area which is of high magnitude and is uniform along the length of the arc path.

As is well known in the circuit breaker art, the are which appears across disengaging contacts is effectively interrupted by drawing the are into an arc chute to thereby lengthen, constrict and cool the'arc. The driving force which drives this arc in the arc chute is provided bya magnetic field which is so directed as to coact with the magnetic field of the arc.

The force driving the arc in the arc chute is therefore proportional to the product of the fiux density of the magnetic field and the magnitude of the current in the arc. Therefore if the designer can increase the flux density of the magnetic field the force on the arc will be increased and the arc chute can be modified to provide more effective cooling and elongation of the arc to result in more effective arc interruption.

It is therefore an object of my present invention to proneticstructure with two blowout coils wound in bucking vide a magnetic field having a higher flux density than has heretofore been used.

Clearly, it is desirable to have this magnetic field, which is usually created by blowout coils of well known design, of large magnitude to thereby more effectively drive the arc into its arcing chamber. Similarly, it is desirable to provide for uniformity of the magnetic field along the length of the arc chute in order that no portion of an arc chute will be subjected to a disproportionate share of the effects of the arc voltage.

Another desirable property which this driving magnetic field should have is that the phase shift between the magnetic field intensity and the arc current be small. If this were not the case, the arc current, after passing through a current zero, would actually be driven downward and away from the arc chute during that period of time before the magnetic field also passes through zero. This condition will then result in restrikes in the arc chute and possible failures.

Since this phase shift or the lag of the flux with respect to the current is caused by iron losses in the magnetic circuit, the magnetic circuit is formed of an interleaved laminated iron structure. These laminations maybe of any appropriate material such as the silicon irons used for transformers to thereby allow a closer phase relationship between the flux and the arc current.

It has been found that in presently used magnetic structures, the field is weak and is not uniform along the length of the arc. Similarly, the phase shift between the magnetic flux and the arc current has been found to have an appreciable magnitude. Furthermore, adding turns to the blowout coil which passes the magnetornotive force through this structure increases the flux density in the air gap by only a very small amount.

The principle of my invention is to use a closed magrelationship. More specifically, the two blowout coils are of identical design and are connected electrically in series. They are furthermore introduced into the arc current circuit by meansof a single jump gap. Extensive tests, the

results of which will be presented hereinafter to emphasize the advantages of my novel construction, have shown that the flux across the length of the enclosed air gap is substantially uniform and of a higher magnitude than was obtained with any previously used structure.

current and the magnetic flux in the magnetic structure of my invention for driving the are into the arc chamber can be decreased to a substantially negligible amount by forming the magnetic circuit of interleaved laminations which are parallel to the flux in the air gap. This type of laminating shall be referred to hereinafter as horizontally laminated, this being the term used in the circuit breaker industry.

Accordingly, a primary object of my invention is to provide a closed magnetic structure for are chutes having blowout coils which are in bucking relationship with one another. I p

Another object of my invention is to provide a closed magnetic structure for are chutes having two series blowout coils of identical design which are in bucking relationship with oneanother and are introduced into the circuit by means of a single jump gap.

Another object of my invention is to provide a magnetic the arcing chamber and is' of high magnitude.

A still further object of my invention is to provide a magnetic core having a first and second blowout coil thereon for providing fluxes in bucking relationship with one another wherein the magnetic core is horizontally laminated to providea negligible phase shift between the magnetic field within the area encircled by the closed core and the current flowing through the series connected blowout coil. v

Still another object of my invention is to provide a magnetic structure for are chutes in which the magnetic core is horizontally laminated with interleaved laminations of high grade iron to thereby decrease phase shift between the magnetic field and the arc current.

Another object of my invention is to provide a magnetic structure which comprises a closed magnetic core and a first and second coil wound on said core to provide fluxes in bucking relationship wherein the flux within the area encircled by said core is uniform, of high strength, and the phase shift between the magnetic flux within the encircled area and the current in the coils can be made negligible by horizontally laminating the enclosed magnetic core.

These and other objects of my invention will become apparent in the following description when taken in connection with the drawings in which:

Figure 1 shows an example of a circuit breaker to which my novel magnetic structure may be applied.

Figure 2 indicates the operation of the circuit breaker of Figure 1 and further indicates how the blowout coils of my invention areinserted into the circuit to carry the.

arc current. p v s Figure 2a showsthe jump gapportion of Figures 1 and 2 in greater detail; I T

Figure 3 showsan exploded perspective view of arcing Patented Apr. 22, 1958:

I plates in conjunction with my novel magnetic structure. When the arcing plates are inserted within the air gap of my novel structure the are which is created by disengaging circuit breaker contacts will be driven up the constricting arcingslots by the field .of the magnetic structure.

Figure 4 a similarly shows my novel magnetic structure.

Figure 4b shows a magnetic structure which operates according .to a different principle than does my novel structure.

Figure 4c similarly shows a magnetic structure which operates differently from my novel magnetic structure.

Figure 4d shows still another magnetic structure having different operating principles than does my novel magnetic structure.

Figure 4e shows measured curves for each of the magnetic structures shownin Figures .4athrough4d in which flux density liS plotted as a function of the length along the :arc chute wherein magnetomotive force is a param eter.

Figure 5 shows-a schematic representation of the structure :of Figure 3 when :appliedto -a circuit breaker application.

Figure 6 shows an oscillogram of exciting current and the magneticsfield in-theairgap-plotted on the same time axis fora magnetic structure made in accordance with my invention and being vertically laminated.

Figure 7 shows an oscillogram of exciting current andthe magnetic field in the air gap plotted on the-same time axis for amagnetic structure made in accordance with-my invention and being horizontally laminated.

Figure 1 is shown here merely to provide a setting for mynovel invention. Since devices of this type-are well known, only a cursory description will be given.

The figure ;shows :a first and second terminal 10 and 11, respectively, whichhareengaged and disengaged by means of the movable contact arm 12 which, when driven by the operatingmechanism indicated generally as 13 and 14, drives the movable-contact 15 into contact engagement with the fixed-contact16. The arcing contacts are then shown as comprising contact 17 on the stationary structure and the element 18 on the movable contact structure 12.

;It is now clearthat undernormalcurrent carrying conditions, the current path, as shown by the heavy line, follows the path of the letters A, B,.C, D. That is, the current path comprises terminal 10, the cooperatingcontacts :15 ,and 16, themovable'contact arm .12 and the second terminal 11.

Thestructure which is then provided todeal with the are which willbe created upon-disengagement of the movable contacts is-shown ascornprising the jump gap 19,.and the arc runners.2 0xand"21 which will-guide the are into the arcing chamber.

More specifically, 'thehjump-gap 19 is constructed of refractory material and containshorizontalplates which facilitates the .quick insertion ofthe -blowout coil upon contactparting. 'As .will be more fully described hereinafter, the jump, gap 19 extinguishes the arc between the stationary. arcing ,contact17 and the lower endof the rear arc-runner to which theblowout coil is connected.

The blowout coils which, in accordance with my novel invention, are wound in bucking relationship withon another, are shown as coils 22 and 23, and are wound on the closed magnetic structure .24. The ma gnetic structure coming across'the frontof the circuitbreaker is indicated by the dotted line 24' and this-magnetic structure clearly encircles the arcing area of the circuit breaker. Within this area, there will, of course, be arcing plates for lengthening and constrictingthe are, as clearly shown 111 copending application Serial No. 322,027, filed November 22, 1952.

The blowout coil 22 is shown as having a first terminal 25 and a second terminal 26. Similarly, the blowout coil-23 has, a first terminal 27,. anda second-,terminal28.

The section marked with the dotted circle 2:: in Figure 2, is shown in Figure 2a, where conducting member 29 is fastened to the conductor 29a by means of the fastening device 29b. The conductor 29a which is positioned below the jump gap is connected to the stationary contact structure by means of the disconnect contacts indicated generally at 19a.

The terminal 30, which is electrically isolated from conducting member 29 is positioned generally behind the conducting member 29 as shown in Figure 2a and is connected to the terminal 25 of Figures 1 and 2 by means of the conductor 25a.

As seen with reference to Figure 2, the blowout coils 22 and 23 of my invention have a common connection between the terminals 26 and 27 and the terminal 25 is connected at the point 30. As will be more clearly indicated, this type of connection will force the blowout coils 22 and 23, upon the occurrence of an arc across the circuit breaker contacts, to be placed in series relationship. These coils are then further wound to create a fiux within the magnetic structure 24 which are in opposing directions.

This is shown in Figure 2 where the movable contact structure 12 when in the dotted position has begun to separate from the stationary contacts 16 and 17. The current path at this time will deviate from the path shown in Figure l and will assume the path marked E. That is, the current will enter the terminal 10 at point A, thereafter flow to the arcing contact 17, jump across the small air gap and into the movable arcing contact structure 18 through the movable contact arm 12 and thereafter flow hack to the circuit breaker terminal 11 at point D.

This arc will travel up towards the arc chute very rapidly and will subsequently jump the jump gap 19 to assume the current path marked F. Hence, the current now flows from the terminal 10 across the jump gap 19 to are runner 20, then to the movable contact structure 12 and thereafter to the lower circuit breaker terminal 11.

After extinction of the arc across the jump gap 19, the blowout coils are in the arcing circuit, the current path being that shown in Figure 2 as path H which comprises the terminal 10, the stationary contact structure, conductor 29, terminal 28, coil 23, terminal 27, terminal 26, coil 22, terminal 25, terminal 30, are runner 20, the arc itself and the terminal 11.

Continued movement of the contact arm 12 to its disengaged position will stretch the are out between the end of arc runner 29 and the arcing contact 18 of the movable contact structure 12 until such a time that the arc will prefer to take the path shown by the letter I to the arc runner 21 and the movable contact structure 12 will now be relieved of allarcing dutyand the circuit to the lower terminal 11 is-completed by the conducting member 32.

With the insertion of the blowout coils 22 and 23, in the arcing circuit a magnetic field will now be produced which, in accordance with my invention, is of high magnitude and is uniform along the length of the iron struc ture to thereby drive the are shown in the path indicated by the letter I up the arc runners lfland 2l to the position of the letter K.

.In this-position, the are is in intimate contact with the cooling plates of the arcchute. The rapid cooling and stretching of the are through the coordination efforts of the magneticcircuit and the cooling plates subsequently produces an extremely fast and etiicient interruption.

Figure 3 more ,specifically shows my, novel magnetic circuitas divorced from the circuit breaker mechanism. Iii-Figure 3, the ,magn etic circuit of my novel invention comprises .the,enclosedmagnetic core 34 which corresponds to-the magnetic core24 of. Figures 1 and 2 and a first, and-second coil 35 and 36, respectively, which correspondto-theblowout coils 23and22 of. Figures 1 and 2.

For illustrative purposes, it is sho,wn that arcing plates 37whichareused to elongate cpnstrictand cool the arc,

may be inserted within the area encircled by the magnetic structure 34 for circuit breaker applications wherein the magnetic field in the encircled area would coact with the magnetic field of the arc to thereby drive it into the notches of the arcing plates 37. Although the notches of plates 37 of Figure 3 are shown as being tapered, they couldhave been of any other variety known to the circuit breaker art such as center slot, off center slot, modified taper, etc.

As clearly shown in Figure 3, the essence of my novel invention is to energize the coils 35, 36 from their terminals 38, 39 and 40, 41 in such a way as to drive the current I in the coil 35 and I in the coil 36 so as to produce a fiux 35 due to the coil 35 and a flux 36 due to the coil 36 whereby these two fluxes are in bucking relationship. Although these coils could be. energized from separate and independentsources, it may be desirable for circuit breaker applications that these coils be identical and be connected in series to thereby assure the creation of an exactly equal and opposite bucking flux in view of the identical. current in the coils and the equal iron cross section. V

A schematic view of the structure of my novelstructure is shown in Figure 5 which shows the device being used in conjunction with a circuit breaker. In Figure 5 I have schematically shown the circuit breaker contacts 50 in the engaged position whereby a power source 51 energizes a load 52. Coils 35 and 36 which are shown to be connected in series are aswas described hereinbefore inserted into the arc current circuit after the jump gap 53 extinguishes the are between points A and B after contacts 50 .are disengaged. When the coils 35 and 36 are put into the circuit and a current I flOWs therethrough, a flux 45 will flow in the area enclosed by the magnetic structure 10, which flux forces the are into the arc chamber. It is to be specifically noted in Figure 5 that the flux gb,

indicated by the arrows across the air gap of the magnetic structure 34 is substantially equally distributed across the length of the air gap. This feature, which is inherent in the practice of my novel invention, allows a substantially equal force to be applied along the entire length of the arc to thereby allow more effective are interruption.

As is further shown in Figure 3, the magnetic core 34 is constructed of horizontally laminated magnetic strips wherein the ends or corners of the magnetic structure have these individual magnetic sheets interleaved. I have found this construction to be desirable when it is necessary to have the phase shift between the fluxes in the area encircled by the magnetic core 34 and the current in the coils 35 and 36 at a negligible magnitude.

This may be seen in the oscillograms shown in Figures 6 and 7. These oscillograms are basedon the oscillograms presented in the publication Flux measurements in magnetic air circuit breaker interrupters, by W. A. Carter, American Institute of Electrical Engineers, Transactions, Paper No. 5460, made available for printing April 20, 1955.

Referring first to Figure 6 which plots current and magnetic air gap field on a common time axis for the case of a vertically laminated structure, it is seen that there is an appreciable phase shift between the zero point of the magnetic field and the zero point of the current. In the particular structure measured this phase shift was 53.

When however the magnetic structure is horizontally laminated, the similar measurement of Figure 7 shows that the phaseshift between the exciting current and the magnetic air gap field arising therefrom is negligible. 7

Referring now to Figures 4a through 4e, it is seen that Figure 4eshows the flux density as a function of length along an arc chute with the magnetomotive forces as a parameter for the various magnetic structures shown in Figures 4a through 4d where Figure 4a is the structure of my novel invention. Itis to be noted thatthe fields have been plotted as per unit quantities in order to allow direct comparisons between the measured results for each of the embodiments. These curves have been measured and the results presented in the publication Flux measurements in magnetic air circuit breaker interrupters, by W. A. Carter, American Institute of Electrical Engineers, Transactions, Paper No. 55-460, made available for printing April 20, 1955.

It is to be further noted that the dashed portions of the curves in Figure 4d represent projected field symmetry.

The structure shown in Figure 4b comprises two identical horizontally laminated structures. It is seen,

however, in the curves of Figure 4e that in using this structure the fiux density within the air gap is not uniform and drops severely along the middle of its length.

Similarly, the field due to the structure shown in Figure 4c is, as would be expected, not uniform along its length. This structure, which is also horizontally laminated, has a reduction in field strength of the order of as is indicated in Figure 4e.

Similarly, the structure of Figure 4d shows a nonuniform field and since this structure is verticallylaminated, it shows the additional drawback of large phase shift between the flux and the actuating current.

It is now clearly seen that the structure Figure 4a which is the structure of my novel invention shows a highly uniform field throughout its entire length, this field being appreciably greater in magnitude than any of the other structures considered. Furthermore, by horizontally laminating the encircling magnetic core shown in the construction of Figure 4a, it is obvious that eddy currents can be so reduced as to make phase shift between the magnetic flux in the air gap and its actuating current to be negligible.

Although I have described preferred embodiments of my novel invention, it will now be apparentthat many modifications and variations may be made by those skilled in the art., I prefer to be limited,- therefore, not by the specific disclosure herein but only by the appended claims.

I claim:

1. In a circuit breaker comprisinga pair of cooperable contacts having an engaged and disengaged position; a first means to move and maintain said cooperable contacts in said engaged position, automatic means operatively connected to effect movement of said cooperable contacts to said disengaged position in response to a predetermined electrical condition; are extinguishing means comprising an arc chute and fiux generating means; said are chute having a plurality of arc plates operatively positioned to receive an are formed when said cooperable contacts are moved to said disengaged position; said flux generating means being comprised of a magnetic structure for distributing fluid in an air gap at said are chute to co-act with an arc to thereby drive said are into said are plates of said are chute; said magnetic structure comprising a magnetic core and afirst and second winding; said magnetic core comprising interleaved magnetic. laminations which are horizontally laminated and encircle said air gap; said first and second windings being connected in series and wound on said magnetic. core to produce oppositely directed magnetic fluxes insaid magnetic core when current flows in said first and second windings.

comprising an arc chute and flux generating means; said are chute having a plurality of arc plates operatively positioned to receive an are formed when said cooperable contacts are moved to said disengaged position; said flux generating means being comprised of a magnetic structure for distributing fluid in an air gap at said are chute to cq-act with an arc to thereby drive said are into said are pl tes of saidiarc' chute; said magnetic structure comprising'i'a magnetic coreand a' first and second winding; said magnetic core comprising interleaved magnetic laminations which arehorizontally laminated and encircle said air gap;said first and second'windings being connected in series and wound on said magnetic core to produce oppositely directed ma gnetic fluxes in said magnetic core when currentfiows in said first and second windings; the phase shift between the flux in said air gap which arises upon flow of current'in said first and second windings being of substantially negligible magnitude.

3. In a circuit breaker comprising a pair of cooperable contacts; a first means to move and maintain said cooperable contacts in engaged position; automatic means to disengage said cooperable contacts in response to a predetermined electrical condition; are plates having notches positioned to receive anarc formed when said cooperable contacts disengage and flux generating means for creating a magnetic field to coact with the magnetic field of said arc to'the rebydrive said are into the notch of said are plates; a second'means'being provided to energize said flux generating means by the current flowing in said arc; said flux generating means comprising an enclosed magnetic core and a first and second blowout coil wound on said magnetic core; said second means being constructed to pass arc current through said first and second blowout coil; said first and secondblowout coils being wound to create oppositely directed fluxes responsive to the flow of arc current therethrough to thereby create a uniform magnetic field of substantial magnitude throughout the area encircled by said magnetic core.

4. In a circuit breaker comprising a pair of cooperable contacts; a first means to move and maintain said cooperable contacts in engaged position; automatic means to disengage said cooperable contacts in response to a predetermined electrical condition; are plates having notches positioned to receive an are formed when said cooperable contacts disengage and flux generating means for creating a magnetic field to coact with the magnetic field of said arc'ltothereby drive said arc into the notch of said are plates; a second means being provided to energize said flux generating means by the current flowing in said arc; said flux generating means comprising an enclosed magnetic core and a first and second blowout coil wound on said magnetic core; said magnetic core comprising interleaved magnetic laminations which are horizontally laminated; said second means being constructed to pass arc current through said first and second blowout coil; said first and second blowout coils being wound to create opposite fluxes responsive to the flow of arc current therethrough to thereby create a uniform magnetic field of substantial magnitude throughout the area encircled by said magnetic core.

5. In a circuit breaker comprising a pair of cooperable contacts; a first means to move and maintain said cooperable contacts in engaged position; automatic means to disengage said cooperable contacts in response to a predetermined electrical condition; are plates having notches positioned to receive an arc formed when said cooperable contacts disengage and flux generating means for creating a magnetic field to coact with the magnetic field of said are to thereby drive said are into the notch of said are plates; a second meansbeing provided to energize said fluxgenerating means by the current flowing in said arc; said flux generating means comprising an enclosed mag-- netic core and a first and second blowout coil wound on said magnetic core; said first and second blowout coils being' connected in series; said second means being constructed to pass arc current through said first and second blowout coil; said first and second blowout coils being wound to creat e opposite fluxes responsive to the flow of arc current therethrough to thereby create a uniform magnetic field of substantial magnitude throughout the area encircled by said magnetic core.

6. In a circuit breaker comprising a pair of cooperable contacts; a'firs't means to move and maintain an cop'- era'ble contacts in engaged position; automatic mean's lto disengage said cooperable contacts'in response to time determined electrical condition; are plates having notches positioned to receive an are formed when said cooperable contacts disengage and flux generating means for creating a magnetic field to coact with the magnetic field of said are to thereby drive said are into the notch of said are plates; 3. second means being provided to energize said flux generating means by the current flowing in said arc; said flux generating means comprising an enclosed magnetic core and a'first and second blowout coil wound on said magnetic core; said magnetic core comprising'interleaved magnetic laminations which are horizontally laminated; said first and second blowout coils being connected in series; said second means being constructed to pass arc current through said first and second blowout coil; said first and second blowout coils being wound to create oppositely directed fluxes responsive'to the flow of arc current therethrough to thereby create a uniform magnetic field of substantial magnitude throughout the area encircled by said magnetic core; the phase shift be tween the flux in said air gap and the current in said first and second windings being of substantially negligible magnitude. l i

7. In a circuit breaker comprising a pair of cooperable contacts; means to move and maintain said cooperable contacts in engaged position; automatic means to disen gage said cooperable contacts in response to a predetermined electrical condition; means to extinguish arcs formed when said cooperable contacts are moved to said disengaged position; said arc extinguishing'ineans cornprising a plurality of slotted plates positioned't'o receive the are created when said cooperable contacts disengage and a magnetic circuit comprising a magnetic core encircling said plates and a first and second blowout coil; said first and second blowout coils being connected in series and being wound on said magnetic core to produce opposing fluxes in said core when current flows in said first and second coils; circuit means being provided to pass arc current through said first and second blowout coil upon creation of an arc to thereby initiate a substantially uniform magnetic field across said tapered plates to force said are to travel up the tapered slots of said plates.

8. In a circuit breaker comprising a pair of cooperable contacts; means to move and maintain said cooperable contacts in engaged position; automatic means to disenigage said cooperable contacts in response to a predetermined electrical condition; means to extinguish arcs formed when said cooperable contacts are moved to said disengaged position; said are extinguishing means comprising a plurality of slotted plates positioned to receive the are created when said cooperable contacts disengage and a magnetic circuit comprising a magnetic cor lencircling said plates and a first and second blowout coil; said first and second blowout coils being connected in series and being wound on said magnetic core to produce opposing fluxes in said core when current flows insaid first and second coils; circuit means being provided t'o pass arc current through said first and second blowout coil upon creation of an arc to thereby initiate a substantially'uniform magnetic field across said plates to force said are to travel up the tapered slots of said plates;'said magnetic core being formed of horizontally stacked interleaved laminations to thereby reduce the phase shift between the arc current and the magnetic field acting on said arc.

9. In a circuit breaker comprising a pair of cooperable contacts having an engaged and disengaged position; a first means to move and maintain said cooperable contacts in said engaged position, automatic means operatively connected to effect movement of said cooperable contacts to said disengaged position in response to a predetermined electrical condition; arc extinguishing means prising an arc chute and flux generating means; said are chute having a plurality of arc plates operatively positioned to receive an are formed when said cooperable contacts are moved to said disengaged position; said flux generating means being comprised of a magnetic structure for distributing fluid in an air gap at said arc chute to co-act with an arc to thereby drive said are into said arc plates of said are chute; said magnetic structure comprising an enclosed magnetic core and a first and second blowout coil; said first and second blowout coils being inserted in series with said are upon its occurrence; said first and second blowout coils being wound to induce oppositely directed fluxes in said magnetic core upon passage of arc current through said coils; the magnetic field in the area encircled by said magnetic core being directed to interact with the magnetic field of said are to drive said are into said are plates of said are chute.

10. In a circuit breaker comprising a pair of cooperable contacts having an engaged and disengaged position; a first means to move and maintain said cooperable contacts in said engaged position, automatic means operatively connected to effect movement of said cooperable contacts to said disengaged position in response to a predetermined electrical condition; arc extinguishing means comprising an arc chute and flux generating means; said arc chute having a plurality of arc plates operatively positioned to receive an are formed when said cooperable contacts are moved to said disengaged position; said flux generating means being comprised of a magnetic structure for distributing fluid in an air gap at said arc chute to co-act with an arc to thereby drive said are into said are plates of said are chute; said magnetic structure comprising an enclosed magnetic core and a first and second blowout coil; said first and second blowout coils being inserted in series with said arc upon its occurrence; said first and second blowout coils being wound to induce oppositely directed fluxes in said magnetic core upon passage of arc current through said coils; the magnetic field in the area encircled by said magnetic core being directed to interact with the magnetic field of said are to drive said are into said are chute; said magnetic field created within the area enclosed by said are chute being substantially uniform to thereby act uniformly over the are within the area of the magnetic'field of said magnetic structure.

11. In a circuit breaker comprising a pair of cooperable contacts having an engaged and disengaged position; a first means to move and maintain said cooperable contacts in said engaged position, automatic means operatively connected to effect movement of said cooperable contacts to said disengaged position in response to a predetermined electrical condition; arc extinguishing means comprising an arc chute and flux generating means; said are chute having a plurality of arc plates operatively positioned to receive an are formed when said cooperable contacts are moved to said disengaged position; said flux generating means being comprised of a magnetic structure for distributing fluid in an air gap at said arcchute to co-act with an arc to thereby drive said are into said i arc plates of said are chute; said magnetic structure comprising an enclosed magnetic core and a first and second series connected blowout coil; said first and second blowout coils being inserted in series with said are upon its occurrence; said first and second blowout coils being wound to induce oppositely directed fluxes in said magnetic core upon passage of arc current therethrough; the magnetic field in the area encircled by said magnetic core being directed to interact with the magnetic field of said are to drive the said are into said are chute; said mag-, netic field created within the area enclosed by said are chute being substantially uniform.

12. In a circuit breaker comprising a pair of cooperable contacts having an engaged and disengaged position; a first means to move and maintain said cooperable contacts in said engaged position, automatic means operatively connected to effect movement of said cooperable contacts to said disengaged position in response to a predetermined electrical condition; are extinguishing means comprising an arc chute and flux generating means; said are chute having a plurality of arc plates operatively positioned to receive an are formed when said cooperable contacts are moved to said disengaged position; said flux generating means being comprised of a magnetic structure for distributing fluid in an air gap at said arc chute to co-act with an arc to thereby drive said are into said are plates of said are chute; said magnetic structure comprising an enclosed magnetic core and a first and second blowout coil; said first and second blowout coils being inserted in series with said are upon its occurrence; said first and second blowout coils being wound to induce oppositely directed fluxes in said magnetic core upon passage of arc current therethrough; said magnetic core being formed of horizontally stacked interleaved laminations to thereby reduce the phase shift between the arc current and the magnetic field acting on said are; the magnetic field in the area encircled by said magnetic core being directed to interact with the magnetic field of said are to drive the'said are into said are chute.

13. In a circuit breaker comprising a pair of cooperable contacts having an engaged and disengaged position; a

first means to move and maintain said cooperable contacts in said engaged position, automatic means operatively connectedto effect movement of said cooperable contacts to said disengaged position inresponse to a predetermined electrical condition; arc extinguishing means comprising an arc chute and flux generating means; said are chute having a plurality of arc plates operatively positioned to receive an are formed whensaid cooperable contacts are moved to said disengaged position; said flux generating means being comprised of a magnetic structure for distributing fluid in an air gap at said are chute to co-act with an arc to thereby drive said arc into said arc plates of said are chute; said magnetic structure comthe arc current and the magnetic field acting on said arc; t

the magnetic field in the area encircled by said magnetic core being directed to interact with the magnetic field of said are to drive said are into said are chute; said magnetic field created within the area enclosed by said magnetic structure being substantially uniform to thereby act uniformly over the arc within the area of the magnetic field of said magnetic structure.

14. In a circuit breaker comprising a pair of cooperable contacts having an engaged and disengaged position; a first means to move and maintain said cooperable contacts in said engaged position, automatic means operatively connected to effect movement of said cooperable contacts to said disengaged position in response to a predetermined electrical condition; are extinguishing means comprising an arc chute and flux generating means; said are chute having a plurality of are plates operatively positioned to receive an are formed when said cooperable contacts are moved to said disengaged position; said flux generating means being comprised of a magnetic structure for distributing fluid in an air gap at said are chute to co-act with an arc to thereby drive said are into said are plates of said are chute; said magnetic structure being constructed of a magnetic core for encircling said air gap and a first and second winding on said magnetic core; said first and second windings being identically constructed; said first and second windings being connected in series and wound on said magnetic core to produce oppositely directed fluxes in said magnetic core when current flows in said first and second windings; the magnati e flux in said airgap being substantially uniform along the-leiigtlfofisaid air gapl v i '15. In a" circuit breaker comprising a pair of cooperable'contacts, an arc extinguishing means, a jump gap and a magnetic structure; said cooperable contacts being movable betweenan engaged and a disengaged position, said cooperable contact drawing an arc upon disengagement thereof; said magnetic structure being positioned with respect to said cooperable contacts and said are extinguishing means to affect interaction between said arc and said are extinguishing means for subsequent extinguishing of said are upon energization of said mag netic structure; said magnetic structure comprising an enclosed magnetic core and a first and second blowout coil wound on said magnetic core; said first and second blowout coils being connected in series and wound to induce oppositely directed fiuxes in said magnetic core upon passage of current through said coils; said lump gap being constructed to force are current to flow through said series connected blowout coils when an arc appears across said cooperable contacts.

16. In a circuit breaker comprising a pair of cooperable contacts, an arc extinguishing means, a jump gap and a magnetic structure; said cooperabie contacts being movable between an enga ed and a disengaged position, said cooperable contact drawing an are upon disengagement thereof; said magnetic structure being positioned with respect to said cooperable contacts and said are extinguishing means to affect interaction between said are and said are extinguishing means for subsequent extinguishing of said are upon energization of said magnetic structure; said magnetic structure comprising an enclosed magnetic core and a first and second blowout coil wound on said magnetic core; said first and second blowout coils being connected in series and Wound to induce oppositely directed fluxes in said magnetic core upon passage of current through said coils; said first and second coils being identically constructed; said jump gap being constructed to" force are current to flow through '12 said series connected blowout coils when an arc appears across said cooperable contacts.

17. In a circuit breaker comprising a pair of cooperable contacts, an arc extinguishing means, a jump gap and a magnetic structure; said cooperable contacts being movable between an engaged and a disengaged position, said cooperable contact drawing an are upon disengagement thereof; said magnetic structure being positioned with respect to said cooperable contacts and said are extinguishing means to affect interaction between said are and said are extinguishing means for subsequent extinguishing of said are upon energization of said magnetic structure; said magnetic structure comprising an enclosed magnetic core and a first and second blowout coil wound on said magnetic core; said first and second blowout coils being connected in series and wound to induce oppositely directed fluxes in said magnetic core upon passage of current through said coils; said first and second coils being identically constructed; said jump gap being constructed to force arc current to flow through said series connected blowout-coils when an arc appears across said cooperable contacts .said magnetic core being constructed of horizontallj laminatedinterleaved laminations of magnetic material whereby phase shift between the flux the area encircled 'by said magnetic core and the are current flowing in said blowout coils is negligible.

References Cited in the tile of this patent UNITED STATES PATENTS 693,416 Merrick et a]. Feb. 18, 1902 1,606,808 Riley Nov. 16, 1926 2,492,300 Lewis Dec. 27, 1949 2,635,158 Peter T Apr. 14,1953

OREIG P T 176,547 Great Britain Mar. 16, 1922 

